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MG MGB Technical - Oil Cooler line rupture

I just returned from a shakedown 1200 mile round trip up and down Donner Summit ( 7227') in California. The 1977 MGB, with a just refurbished engine bay, new HIF 1-1/2" SU carbs, performed wonderfully and roundtrip, I averaged almost 31 MPG ( OD, on the freeway most the time).
Then Murphy woke up. The 5 year new SS braided oil hose I purchased from Moss along with the new oil cooler in 2007 failed. I noticed the oil gauge twitching from 80-60#, then steady when the RPMS ran up. Curious, I pulled over with the engine running and opended the hood to be greeted with a facefull of oil as the rad fans snapped on.
So much for the show quality bay refurbishment!
The long pressure line from the oil cooler to the rear block had a pin hole right off the cooler fitting squirting oil into the rad, and then all over the damn place.
Now, try dealing with that one in the midst of a snow flurry, 5800' elevation, Sat morning, the day before Easter, and no one is home in Reno Nevada.
Of course you should know that I've renewed every single, flexible brake, hydraulic, water, and vacuum line in the car except those two oil cooler hoses in the engine bay/whole car refurbishment effort in the last 3 months.
That'll teach me, eh? Cheers, Vic
vem myers

I haven't used the ss types. I know the Moss rubber ones I bought probably 8 years ago had poorer threaded fittings than the one it replaced. Very light gauge and poorly formed threads. No leaks but I was nervous for awhile.

I had trouble with a Moss sourced SS braided hose from the block to my oil gauge. It leaked almost immediately at the crimp fitting. I replaced the crimp with a worm clamp and all has been okay. Lot's of complaints about these gauge hoses in the archives.

I'm debating going back to the metal pipe I had from the block to the filter adapter and forgetting the cooler. Here in NH I don't really need the cooler much. My 18V has the hanging cartridge filter.

Bob
65 Roadster
Robert McCoy

I've had the 4 stainless steel braided lines, along with the oil thermostat, going on 12 years now with no real difficulties. The only weakness is where the lines go into the cooler. This area tends to get peppered with fine grains of sand and rock. Mine were looking a bit beat up so I coated them in Liquid Tape. This has sealed out any air from getting to the pitted areas and seems to have halted the deterioration of the fittings. I carry a rubber bypass hose, in the boot, just in case the oil cooler should fail or a main line blows out. RAY
rjm RAY

The quality of aftermarket hoses is atrocious. I've only replaced a few in recent years but they were all dubious, and some failed quickly. Find a real hydraulic shop and get them made. If you have the OE hoses, the ends can be reused in various ways, or British hydraulic fittings are pretty common worldwide, due to lots of Brit machinery having been exported.

FRM
FR Millmore

I concur with FRM, Get a hydraulic shop to make up your lines. The one I use supply to the industry. Big machines, if any lines failed on these, definitely a negligence suit. They are hand made most lines and well inspected. Mike
J.M. Doust

FRM - very important advice for oil, brake and fuel lines - including those without patent ends. In the UK, Hyphose has everything the MG needs.

RW
R Walker

Great insights and so true. I give. Like Mr. McCoy above, I'm gonna just eliminate the oil cooler with the stock byepass. The engine will run a bit better with a hotter oil, eh? Vem
vem myers

Generally true, but you happen to live in one of the few places where an oil cooler is justified. High speeds up long mountains for many miles, in 100+F temps. Maybe you oughta get an oil temp gauge, at least for test purposes. Modern multimeters have thermocouple inputs. You can get long leads (Omega Engineering) and just tape the TC to the lines etc, and drive while watching the meter.

FRM
FR Millmore

Good Idea FRM. I had a leaky oil cooler when I bought the car. It had already been disconnected. The temp has never ever climbed to a high level, even in the summer. Then again, I've not taken it on a really long run! If I put a new oil cooler back, a proper thermostat and an oil temp guage then? Mike
J.M. Doust

Mike-
"The temp has never ever climbed to a high level, even in the summer."
If you do not have an oil temp gauge, you have no clue what oil temp is; there is little relationship to water temp, until things get very hot indeed. A car with good cooling can have water temp sit at whatever the water stat is forever, while oil temp goes wildly up and down. The water can be at stat temp, but it takes minimum 20 minutes to get oil temp up from cold, under load - not traffic lights or at idle. OTH, water temp can be steady at 180 or 190F, and oil temp can be anywhere from 100F to 300F, depending on ambient temp, airflow, coolers, and load. Some vehicles use water cooled/heated oil "coolers", to prevent either excessively cold or hot oil, both being evil. I spent a lot of hours watching this in my big truck over near a million miles; it has water/oil intercooler, plus turbo intercooler. Despite water temp steady at 180, oil temps would run 150-220 depending on load, and if water temps went up, oil temps could near 250F, at which point you back off or shutdown.

If you have an oil Tstat and cooler, the stat should be doing the watching and thinking for you, so you do not need an oil temp gauge, except for idle info & entertainment. In most climates under most conditions, the oil stat probably stays closed all the time, but you cannot be certain without the OT gauge. Australia might be the other place where an oil cooler is appropriate.

In most climates under most conditions, the oil/water intercooler is far better than any other option, unfortunately not widely appreciated or available. I think turbo Mini had them, but we never got any of those. Mazda use them, also as the Mini, a sandwich plate under the oil filter. The Mini/1100/1300 is the rare car that pretty well always needs a cooler in summer, as the gearbox converts so much power to heat in the oil. I've not seen a Landcrab, since we didn't get those either, but if the gearbox is like the A series transverse cars, the same would apply.

FRM
FR Millmore

"If you do not have an oil temp gauge, you have no clue what oil temp is"

The oil pressure gauge will tell you the temperature is going up, especially at idle.
PaulH Solihull

This thread was discussed between 10/04/2012 and 14/04/2012

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